I picked up a good used RF 1500.1D( I think is the model) on ebay about a year ago for about 250 shipped Pounds the hell out of my Kicker S15L7. Good strong amp 1500W at 2 OHM RMS ,
Good Luck

HD

 

take a look into the autotek line of amps. even though the specs make them to look like puny amps they are not. my old autotek was rated at 50x2 but was measured at 720ish x 2 at a 2ohm load. another one you may want to look into is the old alpine v12 mrv107. it was rated at 455x2 at 2ohms rms. mine measured in at 946 x 2 at 2ohms. these can still be had for around 300 on ebay. i have had both these amplifiers and they were both monsters when ran a certaint way. i still have my alpine which still needs to be repaired but alpine quoted me 200 so its not soo bad considering i paid almost 900 for it brand new in 2001.